This invention relates to a power drivable chuck, and particularly to a chuck having opposing clamping segments for clamping a shank with the chuck.
For many years, chucks have been used to grip or mount the shanks of bits for a variety of purposes, including the mounting of rotary bits for use with a hand or power tool. In many instances, chucks have included a plurality of movable bit-engaging jaws mounted within an opening of a chuck body. The jaws can be manipulated to clamp the shank of a bit which has been inserted into the opening of the chuck. In this manner, the bit is retained with the chuck which, in turn, is mounted on the hand or power tool. The jaws of such chucks may be operated by use of an external implement, such as a conventional chuck key, or by rotational, or xe2x80x9ckeyless,xe2x80x9d elements on the chuck employed in a direct-insertion technique.
Other chucks of the past were designed to allow the bit to be inserted directly into the opening of the chuck using a direct-insertion mounting technique, whereby the bit is locked in assembly with the chuck by virtue of structure within a body of the chuck and on the bit. Such structure includes spherical elements which are typically movable axially and radially, and are in direct contact with the shank being gripped.
There is a need for a chuck which will provide for a sturdy clamping or gripping of the shank in anticipation of significant stresses encountered by the shank during a work effort. Further, there is a need for a chuck which will provide such sturdy clamping or gripping while facilitating a xe2x80x9ckeylessxe2x80x9d or direct-insertion assembly of the shank with the chuck.
While some of the above-noted chucks are adapted to receive and mount the shanks of bits by insertion of the bits directly into the bit-receiving opening of the chuck, the opening is typically designed to receive only shanks of bits with a common diameter or size, consistent with the diameter or size of the opening. Thus, a set of bits of different diameters at the working ends thereof would each be required to have a chuck-mounting shank diameter which is the same as the shank diameter of the remaining bits of the set. This leads to a situation where the bit shank, in order to be strong enough to handle the forces and torques imposed on the larger bits of a range of sizes employed, is much larger than needed, and thus uneconomical, for the smallest bits of the set.
Thus, there is a need for a chuck having structure which will facilitate use of the direct-insertion mounting technique for bits having different shank diameters.
Also, with respect to bits which are formed with chuck-mounting shanks of different diameters, there is a need for uniform structure on such shanks to facilitate assembly of each bit with common structure of the chuck when using a direct-insertion mounting technique.
In addition, there is a need for a chuck and bit assembly having structure which facilitates use of the direct-insertion mounting technique where the parameters of the chuck structure are constant and the parameters of the shanks of the bits fluctuates.
It is, therefore, an object of this invention to provide a chuck for a sturdy clamping or gripping of a shank of a bit in anticipation of significant stresses encountered by the shank during a work effort.
Another object of this invention is to provide such sturdy clamping or gripping of the shank while facilitating use of a direct-insertion assembly of the shank with the chuck.
Still, another object of this invention is to provide a chuck having structure which will facilitate use of the direct-insertion mounting technique for bits having different shank diameters.
A further object of this invention is to provide a chuck having structure which facilitates use of the direct-insertion mounting technique where the parameters of the chuck structure are constant and the parameters of the shanks of the bits fluctuates.
With these and other objects in mind, this invention contemplates a power drivable chuck for receiving and clamping a shank, which includes a body having a bore therein formed about an axis thereof. A first clamping segment is located within a first portion, and spaced from the axis, of the bore and is mounted to preclude movement of the segment toward the axis. A second clamping segment is located opposite the first clamping segment within a second portion, and spaced from the axis, of the bore and is mounted to facilitate movement of the segment toward the axis. A first-segment shank-engaging rib extends from the first clamping segment toward the axis, and a second-segment shank-engaging rib extends from the second clamping segment. Means are provided for urging the second clamping segment toward the first clamping segment to clamp the shank therebetween.
This invention further contemplates a power drivable chuck for receiving and clamping a shank, including a body having a bore therein formed about an axis thereof. A first clamping segment is located within a first portion, and spaced from the axis, of the bore. A second clamping segment is located opposite the first clamping segment within a second portion, and spaced from the axis, of the bore. Means are provided for moving at least one of the first and second segments toward the axis of the bore to clamp any shank therebetween. A sleeve is positioned about the body and is movable in an axial direction relative to the body between a retracted position, in which the sleeve is in an unclamped mode, and a forward position, in which the sleeve is in a clamped mode. Means are provided for latching the sleeve wherein the sleeve is latched in the unclamped mode. Means, responsive to the insertion of the shank into the bore of the body, are provided for unlatching the sleeve to allow the sleeve to move toward the forward position.
This invention also contemplates a power drivable chuck for receiving and clamping a shank formed with at least one axially-directed rib, and includes a body having a bore therein formed about an axis thereof. A first clamping segment is located within a first portion, and spaced from the axis, of the bore and is mounted to preclude movement of the segment toward the axis. A second clamping segment is located opposite the first clamping segment within a second portion, and spaced from the axis, of the bore and is mounted to facilitate movement of the segment toward the axis. A first-segment shank-engaging rib extends from the first clamping segment toward the axis. A second-segment shank-engaging rib extends from the second clamping segment. The first-segment rib and the second-segment rib are spaced apart to form at least one spaced groove therebetween for receipt of the rib formed on the shank. Means are provided for urging the second clamping segment toward the first clamping segment to clamp the shank therebetween.
Other objects, features and advantages of the present invention will become more fully apparent from the following detailed description of the preferred embodiment, the appended claims and the accompanying drawings.